1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method that use special toner.
2. Description of the Related Art
In recent years, digital printing technologies have been enhancing their utility values in the on-demand printing market and the market for the printing of small numbers of documents.
In particular, full-color printing using electrophotography has taken precedence over other printing technologies in terms of its productivity, printing cost, and ease of maintenance, and is rapidly gaining market share.
Not only full-color printing by electrophotography using toner of four colors including cyan (C), magenta (M), yellow (Y), and black (Bk), but also multi-color printing using special toner has been getting a lot of attention.
The special printing market having a higher on-demand performance and immediacy is brought into view by the technologies concerning full-color printing using electrophotography.
Special toner may be exemplified by transparent toner that accommodates the irregularity of the surfaces of print materials to realize good gloss, and light toner that is capable of suppressing the roughness of highlighted parts.
The use of the special toner provides a new added benefit different from the benefits achieved in normal digital printing to further enhance the world of the digital printing.
Printing with the special toner may have the drawback of increasing the total amount of toner used in printing, as compared with the four-color printing used in the related art.
In particular, when the special toner is applied in color printing by the electrophotography, the special toner image generated on an intermediate transfer body is typically transferred along with the C, M, Y, and K toner images to a sheet of paper.
The increase in the total amount of toner in each electrophotographic process can thus place a heavier load on the process.
A method of calculating the amount of printed special toner from the amount of toner of the C, M, Y, and K colors is disclosed in Japanese Patent Laid-Open No. 2007-011028.
However, the amount of printed special toner can be zero in the calculation of the amount of printed special toner in the manner disclosed in Japanese Unexamined Patent Application Publication No. 2007-011028. For example, this can happen in a case where the total amount of toner of the C, M, Y, and K colors exceeds a total amount of toner allowed in the print apparatus.
In such a case, it may not be possible to achieve the intended visual effect of the special toner even if a user has performed the printing with the special toner.